Electrical switches having rotatable actuators are used in a variety of applications. For example, it is known to use such switches in gas fueled cooking appliances. An electrical switch assembly is coupled to the rotatable valve stem of the gas valve, to control burner ignition circuitry. When the gas valve stem is rotated to place the valve in the open position and commence gas flow, the burner ignition electrical circuitry is energized to ignite the gas stream at the burner. In this way, stand-by pilot lights are not required, and gas ignition occurs simultaneously with opening the gas valve and commencing the flow of gas. Fuel is not wasted keeping a pilot light burning. Considerable fuel savings can be experienced, particularly in appliances that are used infrequently, with prolonged periods of nonuse. Pilot-less ignition systems conserve fuel and thereby improve appliance efficiency.
U.S. Pat. No. 5,687,836 entitled “ELECTRICAL SWITCH ASSEMBLY ACTUATABLE BY A ROTATABLE MEMBER”, issued Nov. 18, 1997, describes one such electrical switch assembly having utility for gas appliances. While providing many advantages, the switch assembly disclosed therein can be used only for a single circuit, and each switch function in each circuit requires a separate switch.
To improve appliance safety and enhance customer convenience, it is sometimes desirable to include multiple switching functions upon actuation or rotation of a single actuator. A variety of indicator lights to indicate status may be actuated with the primary function, or may be oppositely actuated. For example, it may be desirable to illuminate a “burner on” indicator together with actuation of the ignition circuitry when a gas valve is opened. An electric circuit to indicate ignition failure can be energized upon opening the gas valve, to be illuminated if ignition does not occur within a specific period of time. It may be desirable for various other safety and/or convenience features that are electrically operated to be actuated or de-actuated upon opening the gas valve.
As more and more individual switches for additional functions are combined with a single actuator, the actuator becomes unduly long and complex. Individual switches can be electrically connected, one to another, with only one controlled by the actuator, and others electrically controlled therefrom. However the wiring harness becomes unduly large and complex, and requires significant space for installation. In appliances, it is desirable to minimize space requirements for controls and the like, to maximize area available for appliance functions, for example oven interior space, while minimizing overall appliance size.
U.S. Pat. No. 7,148,440 entitled “STACKABLE SWITCH” issued Dec. 12, 2006, describes a multi-function switch of one type in which multiple switch functions can be stacked one upon another using an intermediate housing member having surface topographies suitable for use in the switches on opposite sides thereof. While the stackable switch disclosed therein provides multi-switching functions in a more compact arrangement than utilizing separate individual switches, in some applications still lower profiles are desirable. For example, to maintain adequate air flow around gas valves associated with the switches, still lower profiles are desirable to minimize the housing and structural dimensions required to contain the gas valves, gas supply systems and wire harnesses.